Evaluating and Modeling the Mechanical Properties of the Prepared PLGA/nano-BCP Composite Scaffolds for Bone Tissue Engineering

In this paper, preparation of nano-biphasic calcium phosphate (nBCP), mechanical behavior and load-bearing of poly (lactide-co-glycolide) (PLGA) and PLGA/nBCP are presented. The nBCP with composition of 63/37 (w/w) HA/beta-TCP (hydroxyapatite/beta-tricalcium phosphate) was produced by heating of bovine bone at 700 degrees C. Composite scaffolds were made by using PLGA matrix and 10-50 wt% nBCP powders as reinforcement material. All scaffolds were prepared by thermally induced solid liquid phase separation (TIPS) at -60 degrees C under 4 Pa (0.04 mbar) vacuum. The results of elastic modulus testing were adjusted with Ishai-Cohen and Narkis models for rigid polymeric matrix and compared to each other. PLGA/nBCP scaffolds with 30 wt% nBCP showed the highest value of yield strength among the scaffolds. In addition, it was found that by increasing the nBCP in scaffolds to 50 wt%, the modulus of elasticity was highly enhanced. However, the optimum value of yield strength was obtained at 30 wt% nBCP, and the agglomeration of reinforcing particles at higher percentages caused a reduction in yield strength. It is clear that the elastic modulus of matrix has the significant role in elastic modulus of scaffolds, as also the size of the filler particles in the matrix.